The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 25, 2022
Filed:
Jul. 11, 2019
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Akira Kanazawa, Tokyo, JP;
Hidekazu Moriki, Tokyo, JP;
Shinya Imura, Tsuchiura, JP;
Yasutaka Tsuruga, Tsuchiura, JP;
Takaaki Chiba, Tsuchiura, JP;
HITACHI CONSTRUCTION MACHINERY CO., LTD., Tokyo, JP;
Abstract
A construction machine that precisely enables derivation of the operation characteristics of hydraulic actuators in a high-velocity area with less calibration operation is provided. A controller () has a calibration mode in which the controller () derives operation characteristics (α(xs)) representing a relation among a spool position (xs) of a meter-in valve (), an operation velocity (Va) of a hydraulic actuator (), and a differential pressure (ΔP) across the meter-in valve (), and is configured to, in a case where the spool position (xs) of the meter-in valve () has changed in a direction to increase the opening area of the meter-in valve () in the calibration mode, output a command signal to increase the opening area of a bleed-off valve () to a bleed-off solenoid proportional pressure-reducing valve () as a command signal to reduce the differential pressure (ΔP).